Regulated power supply systems



Sept. 19, 1961 H. A. CLARKE 3,001,082

REGULATED POWER SUPPLY SYSTEMS Filed Dec. 4, 1957 ZIeetS-Sheet 1 "j ffii-'1 www4? I I :f rf! WW n Sept. 19, 1961 H. A. CLARKE 3,001,082

REGULATED POWER SUPPLY SYSTEMS Filed Dec. 4, 1957 2 sheets-sheet 2 ms/mum /fcr/F/H? ,lf/rfi #mamma l j J j 1 j T 04o l j Z Z J V =1 V- 75 i j? L Y fa/52064# l mils/WMM #fan/ff@ ,1r/7276a Mmmm? l /YJ ffy zo-J ZIJ I I- 22 y ig, l mmm/wm @fer/Hf@ f'/ rif? 60mm/r l O I'* l i :L6 d ffy ,aa/J X22/ l INVENToR. /Zzef Zarka -BY ATTRNEXS" 3,001,082 Patented Sept. 19, 1961 A United States Patent@ F REGULATED POWER SUPPLY SYSTEMS Herbert A. Clarke, Moorestown, NJ., assignor, by mesne assignments, to the United` States of America as represented by the Secretary of the Navy 'Filed Dec. 4, 1957, Ser. No. 700,728

Claims. (Cl. 307-19) 'This invention relates to improved regulated electrical supply systemsand more particularly to improved systems for controlling a plurality of regulated supply circuits.

It is desirable in many applications to combine the output circuits of a number of electrical power supply units of the same ordiferent load capacities to supply one load. In other situations a number of loads may receive power from severalunits of the same or different load capacities. It is necessary, in `some cases, to hold the voltage or current applied to the load or loads constant regardlessof variations in line voltage or load impedance. Under all circumstances, it is desirable to reduce the number, size and weight of the circuit components.

Therefore, it is an object of this invention to provide an improved voltage regulating system controlling'a plurality of kregulating devices in a plurality of power supply circuits. Y 1

Another object of this invention is to provide an improved current `regulating system controlling a plurality of regulating devices in a plurality of power supply circuits.

It is a further object of this invention to provide an improved electrical regulating system controlling a plu,-

rality of regulating devices in la plurality of power supply l units of any capacity connected to any load requirements.

The foregoing objects are achieved by utilizing regulat- FIGURE 2 is a schematic block circuit diagram of a second embodiment of the invention including power units of different lvoltage output having a common control amplifier; and

FIGURE 3 is a schematic block circuit diagram of a third embodiment of the invention including power units of the same current capacity having a common control amplifier arranged to respond to'changes in current output.

Similar reference characters are applied to similar el ments throughout the drawings. v g

Referring to FIG. 1, a plurality of power supply units 10 and 12, of similar voltage output and circuit configuration, are connected in parallel to a load 14. Each of'the power supplies 10 and 12 includes a transformer 16, rectilfier 18, lter 20 and regulator 22. The primary 24 of the transformer 16 of the power supply 1 0 is'connected to a source of alternating current.k The secondary 26 of the transformer 16 -is connected to `a full wave bridge rectifier 18, which is composed, for example, of twelve diodes. The use of a bridge rectifier is desirable to avoid a high peak inverse Voltage on the-diodes. A filter circuit 20 comprising, for example, a series choke 28, shunt capacitor 30 and shunt bleeder resistor 32 is connectedjto the positive output terminal 34 yof the'bridge rectifier 18. A series regulator circuitcomprising, lfor example, atwin triode vacuum tube 22 is connected between the positive ing devices such, for example, as vacuum tubes which regulate current flow in terms of gridl potential. The voltage output of at least one electricalsupply unit in a plurality of units can be sensed, amplified and made to drive the regulators in all units. This avoids the more expensive, space and weight consuming practice of duplicating the sensing and amplification circuitry in each power supply unit. Moreover, the control is simultaneous and equal for all units operating from the same line connection.

The invention finds special importance when an electrica-l system is composed of interchangeable plug-in pack-v ages or modules containing complete circuit functions. For example, a number of basic units may be stacked in parallel to provide loadA current capacity in multiples Yof that of the standard unit. This inventionwould require ,only one controlunitl regardless of the number of supply units.

One embodiment of this invention includes at least two electric supply units,= each unit supplying-'power to the `cathode follower which simultaneously drives the-grids of the regulator tubes regulating the output of the circuit.

The invention will be described in greater detail by reference to the accompanying drawings in which:

FIGURE 1 is a schematic block circuit diagram of one embodiment of the invention including a plurality of electrical supply circuits of the same voltage output, in

combination witha common control device; Y

output terminal 36 of thefilter and the positiveterminal 38 `of the load 14. The anodes 40, 42 ,of the regulator tube 22 are connected to the positive terminal B6 of the filter. The cathodes 44, 46 of said regulatortube 22 are coupled'through overload-limiting cathode -resistors 48 and 50 to the positive terminal 38 of the load 14. The grids 512, 54 of said regulator tube `are decoupled by an isolating resistor 56. Voltage regulation is achieved by controlling the bias voltage on the grids 52 and 54 respectively, as well as thegrids of the corresponding tube in unit 12 by control signals derived from-tbe output of a sensing and control amplifier 58. The negative output terminal 60 of the rectifier 18 output is connected to the second terminal 62 of the load. v I

The control amplifier 58 comprises, forexample, a difference amplifier 64, a pentode voltage amplifier 66, and a cathode follower output amplifier 68, The input circuit of the control amplifier 58 is connected. across the load 14 which is energized by the combined outputs of the power supply units 10 and 12. 'Ille input signal to a first stage 70 of the difference amplifier 64 is derived from a voltage divider composed of a xed resistor 72 and a Variable resistor 74-andapplied `to the -rst grid 76 of a'twin triode difference amplifier 64.v Initially thetap on the variable resistor 74 is adjusted so that the cathodeto-grid potentials of each stage of the twin Vtriode tube 64 aregequal.v This `cathode-.to-grid voltage is `that of the reference voltage which is applied to the grid 78 of the second stage 80 of the difference amplifier64.V The reference voltage may be derived, for example, from a battery 79. Plate potential to the anodes 82 and 84 of the ,second stage v80 since the cathodes 90 and Q2 of the. two stages are connected together.- The output of the second stage 80 is proportional to its cathode-to-gnd potential and hence approximately proportional to the difference between the voltages applied to the grids 76 and 78. An

increase in the output voltage of the combined power supplies 10 and 12 will then increase the output voltage of Vthe difference amplifier 64 and provide a voltage decrease across the anode resistor 88 of the second stage 80. The

tchange proportionally. f

resultant voltage increase tors 94 and 96 to the control grid 98 of a pentode voltage amplifier tube 6 6. ,A pentode is used for Vthe voltage amplifier stage in order to ,provide'a high voltage'gain in a eingle'- stage.- The output ofthe difference amplifier 64k is amplied'andinverted by the pentodeamplier 66 and appears as an increased potential across the load resistor 100 ofthe pentode amplifier 66. By a connection from the anode 102 of the Ypentode amplifier 66 to the ygrid 104 ofthecathode follower 68, the resultant` decrease in the potential'of anode 102 is applied to' the cathode follower 68. `The luse o f a cathode follower is desirable so that the at the anodek 84 is applied y Vthrough avoltage-dividercomprising, for example, resisl cuits, each said circnit'including an electronicvariable 'contrer amplifier' maye'ineiemty ldrive amunipiicity `sf 1 regulator `stages y22 with the attendant high capacitance load Yimposed uponV thisdriving stage. A decrease in voltage thereby ocursacross cathode resistor 105 of the cathode follower 68. Thisl decreased potential is applied 4 yto theV grids `52 and 54j of the regulator tube 22. This reduces the conductance ofthe regulator tube 22 so as to lower the voltageacro'ssi' the load 14 and approach the :initial'conditionf ySimilarly a decrease in the combined p 'output voltage f the -powersupplies would result in an "increased voltage on! the grids 52 and 54 ofthe regulator tube 22; thereby increasing the conductance of the tube 22 so asftfraise the voltage across the load v14 and approach f l the Vinitial condition. To eliminate oscillation in pentode amplifier 66a s eiies combination ofv a resistor 106 and ta capacitor 108 provide the proper phase shift between -thedc'ontrolV grid 98` andy the node`102.' To eliminate' oscillationinthe second stage 8,0 of the'-dierence amplifier A64iafseiiesYcombination of a resistor'llt) and a capacitor '112,f'provi'de' the proper phase shift between 'the plate 84 fand thegrid of the second stage8'0 .of the difference atnplifier'64.` v T1 VIn the second embodiment of the invention shown in --FIG.12, power supply units 10 and 12 of different output `voltages are connected to separate loads 120 and 122.

The eontrolarnplifier 58 is connected to sample the voltage across'k one load 122. The output lof the control am"- plifer is appliedito ajvoltagedivider 124. The grids of the regulatortbe's 221," 22,of'power supplies 10 and 12 fare' then driven with voltages properly proportioned to the outpt'voltages of the individual supply.V In all other respects the operationf this embodiment of the invention -is the saine.` as described with respect to FIG.v l. .This

circuit will properly regulate voltage where similar loads "7.120 and 122are Vaffected by some similar cause so as to t In a third embodiment ofthe invention, shown in FIG. 3,`power Isupply units 10, 12, 13 of the same output` voltageare connected in parallel to load 126. In series 'between the load 126 vand the power suppliesis a temperature Astable precision shunt 128.` vThe control amplifier 'input'is 1connected in parallel with the precision shunt. 'The voltage across thek Ashunt 128 ratherthan the voltage y"across theload is then compared to the reference voltage andused as a measure of load current. The device then vLvoltage regulating apparatus comprising in combination a .plurality of unidirectional voltage supply cirimpedance regulating device, separateY loadmeansconnected to each of said circuits, an electronic sensing device responsive to changes in potential across one of said load means to provide av plurality of control effects and means for separately applying said control effects to control saidregulating devices.

2. Voltage regulating apparatus cornprisingffi'ncombi? nation a plurality of unidirectional voltagesupply circuits, each said circuit including a variable impedance regulating device, loadmeans connected to said circuits, a sensing device responsive to changes in'th-e outputpotential of at least one of said circuits to provideasinglefV control effect, said sensing device comprising connections for a source of reference potential, a difference amplifier connected to saidV reference potential connections `and to said output potential to provide a ydifference potential, a unidirectional current amplifier for amplifying said difference potential, means for applying said control efiect to simultaneously control all ofsaid regulatingdevices,

said last means comprising'a cathode follower and means for connecting said cathode follower to said regulator devices to vary the impedance of said regulator devices in each said circuit according to changes in voltageV across the load. v

3. Current regulating apparatus comprising a plurality of paralleled unidirectional current supply circuits of the same voltage output, each said circuit including an elec,- tronic current regulating device, common loadmeans connected to said circuits, an electrmicV sensing device re-k 's'ponsive to changes in the current output of said circuitsV 4to provide a single control effect and meansfor applying 'said' control effect -to simultaneously control all of said regulating devices. Y

` 4. Current regulating apparatus comprising a plurality of uidirectionalcurrent supply circuits, each said circuit including yan electronic current regulating device, load means connected to each of said circuits, an electronic sensing device responsive to changes in the current output of at least oneY of said circuits to provide a single control -efect and means for applying said control eiect to si- Y 'vmultaneously regulate all of said regulating devices.

5; Current regulating apparatus comprising a plurality of circuitsinparalleL each said circuitinc'luding connections fcr a source of alternating current, a rectifier con-l nected to said source connections, a filter, and paralleled grid-controlled current regulator tubes in'serics with each of saidrv circuits, load means connected to Vsaid circuits,

and single control means for said regulator tubes., said control means comprising connections for a source of reference potential, load current-detectingl means, a differfence,amplifier-.connected to saidpreference potential con-r nectionsY and to Vsaid detecting means to provide a differ A ence potential, a unidirectional currentA amplifier and a cathode follower `for amplifying said difference potential,

and means connecting Ysaid cathode follower to the grids `'of said regulator tubes to vary the limpedance of said regulator 'tubes' in each said circuit according to changes 'in vf the-current through said load means. n n

Y PReferences Cited in the le of this patent Y p y UNITED STATES PATENTS 1 y Mayer ct al. Dec. 28, 1943 2,504,155 Roman Apr. 18, 19501" l v2,512,989 Aicher June 27,1950 l 2,594,006 Friend Apr. 22, 195.2 2,790,133 Day A..-.`.' Apr. 23,1957

'2,806,963 A.Woll ---a Sept. 177, 1957 

